I feel like the timing of this reveal after Anka, the Buried is for the designers to be like "hey, btw guys, its going to be a lot harder for us to make deathrattle cards now that this thing exists so just a heads up." Expect Anka to spike in powerlevel in her last few months in rotation as the designers pump out all the broken death rates they were holding back for a year and a half.
Damn, this card is really, really bad. No immediate impact on turn 9 when you really need to be do something proactive to swing the board back in your favor if you're losing. You're also not going to have many minions in hand to buff at this point unless your deck is way to greedy. Way too often stats just aren't going to be relevant this late into a game.
Do you honestly think it's a good idea to put this in an Anka, the Buried deck when it's so awful on its own? You are not going to find Anka half the time, in which case playing Anubisath Warbringer just loses the game for you.
You might take this as a discover off of Myra Rotspring, but only if your hand is pretty full. It's hard to imagine the other two choices being worse than this.